A fluid transport circuit generally comprises tubes that are connected to one another by coupling devices to which end portions of the tubes are coupled.
A coupling device comprises a tubular body provided internally with an annular sealing element and with an attachment member for retaining the end portion of the tube inside the body in leaktight manner. The body has a central tubular appendix on which the tube end portion is to be engaged, the sealing element being mounted on said appendix so as to be compressed between an outside surface of the appendix and an inside surface of the tube end portion. Such mounting serves to prevent fluid coming into contact with the tube ends, which could lead to a laminated tube becoming delaminated.
During installation, the tubes need to be cut to the correct lengths. On an installation site, such cutting is performed by using a scissors-type pipe cutter. Cutting in that way leads to the end portion of the tube being flattened so that it retains a certain amount of ovalization after being cut. Such ovalization gives rise at the terminal face of the pipe end to a sharp angle that might damage the sealing element. In addition, it makes it difficult to obtain continuous contact between the sealing element and the end portion of the tube. It is therefore necessary to return the tube end portion to a circular section prior to coupling it. To do that, a shaper tool is inserted into the end of the tube, which tool also makes an inner chamfer that facilitates inserting the appendix of the body into the tube end portion. There exist shaper tools that also make an outer chamfer in addition to the inner chamfer.
However, it can happen that the operator performing installation forgets to shape one of the end portions prior to coupling it. The risk of leakage is then very great, either immediately on pressurizing the circuit, or else subsequently.